John Travolta honored his late son Jett in a touching Instagram tribute posted to his account on Wednesday.

The actor shared a black-and-white throwback photo showing Travolta smiling with young Jett in front of him.

"My dearest Jetty, I miss you more than words can say. I think about you everyday. Happy Birthday. Love, your Dad," Travolta captioned the post.

Travolta shared Jett with his late wife Kelly Preston. In 2009, he and Preston’s 16-year-old son died while on a family vacation to the Bahamas. 

Wednesday would have been Jett's 30th birthday.

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In addition to Jett, Travolta and Preston also welcomed daughter Ella, now 22, and son Ben, now 11.

Ella commented on the actor's tribute to Jett, writing, "Happy Birthday Jetty, we love you so much."  

Jett Travolta John Travolta

Jett Travolta is seen with his father, actor John Travolta, in this undated picture. (Rogers and Cowan via Getty Images)

Ella turned 22 in early April and Travolta took to social media to show the two celebrating in England "having afternoon tea."

At the time, Travolta said he was in England shooting "The Shepherd," based on a book by Frederick Forsyth he's "always loved."

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Travolta's tribute to Jett also received a comment from actress Jamie Lee Curtis, who wrote, "Oh John. My hand in yours. X j."

John Travolta, Ella Travolta

John Travolta and his daughter Ella Travolta on "Jimmy Kimmel Live!" (Randy Holmes via Getty Images)

Jett, who was autistic and prone to having seizures, died while the family was on holiday in 2009 after he had a seizure in the bathtub that resulted in a head injury. In 2014, Travolta talked about the loss of his son in an interview at the Theatre Royal Drury Lane, describing Jett’s death as "the worst thing that’s ever happened in my life."

Adding that he didn’t know if he was "going to make it," he said the Church of Scientology helped get him and his family through the loss.

"I will forever be grateful to Scientology for supporting me for two years solid, I mean Monday through Sunday," he said at the time (via BBC). "They didn't take a day off, working through different angles of the techniques to get through grief and loss, and to make me feel that finally I could get through a day."

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He explained in a 2016 interview with "Good Morning America" that the tragedy bonded the family closer together, noting that the birth of Ben shortly after Jett’s death gave them a reason to keep on.

John Travolta Kelly Preston

John Travolta and his wife Kelly Preston, who died in 2020 after a battle with breast cancer. (Anne-Christine Poujoulat/AFP via Getty Images)

"We certainly have bonded together and certainly having little Ben has been a beautiful… you know, kind of glue for us to rebond after tremendous loss," he said.

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The Travolta family also experienced tragedy in July 2020 when Preston died at age 57 after a two-year battle with breast cancer. Travolta has also honored his wife in birthday tributes on social media since her passing.

Travolta family throwback

John Travolta and his family, daughter Ella, son Jett and wife Kelly Preston in an undated family photo. (Rogers and Cowan via Getty Images)

"It is with a very heavy heart that I inform you that my beautiful wife Kelly has lost her two-year battle with breast cancer," Travolta announced on Instagram in 2020 after Preston's death.

"She fought a courageous fight with the love and support of so many," he added. "My family and I will forever be grateful to her doctors and nurses at MD Anderson Cancer Center, all the medical centers that have helped, as well as her many friends and loved ones who have been by her side."